In a product development, CAE is utilized to reduce the cost of development and the design time. In CAE, an analytical model is prepared from a geometric model created by a CAD (Computer Aided Design) system and intensity analysis, thermal analysis, or vibration analysis is conducted on the analytical model using an analysis method such as the finite element method or boundary element method. Creation of an analytical model in CAE requires a large amount of work because it involves the steps of creating a mesh model from the geometric model and specifying parameters and boundary conditions for each element of the mesh model.
With this background, techniques for reducing the workload in analytical model creation have been proposed. JP-A No. Hei03(1991)-70083 discloses a technique that CAD and CAE functions are integrated into one system to reduce workload in creating an analytical model.
Furthermore, JP-A No. 2006-301753 discloses a technique that creates a desired analytical model using an existing analytical model. In this technique, the geometric features of outer surface elements of the existing analytical model are recognized and size data (size constraint) for a modified shape is set so that the mesh is modified under the restrictions of the geometric features and size constraint. Geometric features, such as ribs and holes, can be added or deleted in the technique.
JP-A No. 2003-108609 discloses a technique that creates a desired analytical model using an existing analytical model, as the technique disclosed in JP-A No. 2006-301753. A plurality of correlated reference points are set for the outline of the analytical model to be created and the existing analytical model, and by moving the reference points based on the relations of the reference points and the mesh data of the existing analytical model, the mesh data of the existing analytical model is modified to create the desired analytical model.
If an existing analytical model can be used to create a desired one, the techniques disclosed in JP-A No. 2006-301753 and JP-A No. 2003-108609 considerably can reduce workload in analytical model creation because the steps of creating mesh data and setting boundary conditions are not needed.
As described above, CAE should achieve a reduction of workload in analytical model creation. To achieve this problem, the technique described in JP-A No. Hei03(1991)-70083 integrates CAD and CAE functions into one system. However, this technique has a drawback that it is necessary to create an analytical model again for each geometric modification with CAD, less practical in case of handling huge volumes of data.
On the other hand, the techniques disclosed in JP-A No. 2006-301753 and JP-A No. 2003-108609 are useful since they use existing analytical models to create desired analytical models. These techniques eliminate the need to create mesh data and specify boundary conditions by using existing analytical models to create desired analytical models. This leads to considerable workload reduction in analytical model creation.
However, while the techniques modify the geometry of an analytical model, they do not modify CAD data (geometric model data), which is usually created as an output of the design. Since this geometric model data is also used as manufacturing data, creation of a geometric model is essential in the design stage. Therefore, the techniques have a problem that a final product geometry must be created again by CAD.
The present invention has been made in view of the above circumstances. An object of the present invention is to provide a system and a method for creating a modified analytical model from an existing one and also generating CAD data (geometric model data) of the modified model in order to reduce workload in creation of geometric models and analytical models.